Tag: reflex action

Questions Related to reflex action

The direction of response is opposite in which of the following reflex action?

biology nervous system of man reflex action innate and learned behaviour coordination in human beings- chemical control

  1. Biceps tendon relfex

  2. Knee jerk reflex

  3. Tricep tendon reflex

  4. Withdrawal reflex

Show answer
Correct Option: D
Explanation:

There are 4 types of spinal reflex action, namely the stretch reflex, the Golgi tendon reflex, the crossed extensor reflex and the withdrawal reflex. The direction of response is opposite in withdrawal reflex action. The withdrawal reflex is also called as flexor withdrawal reflex. It protects the body from damaging stimuli. It is polysynaptic. Hence, it causes the stimulation of sensory, association and motor neurons.  For example, when a person touches a hot iron, he withdraws his hand from it within fraction of seconds. In this, the heat stimulates temperature and danger receptors in the skin, triggering a sensory impulse that travels to the central nervous system. The sensory neuron synapses with interneurons and connects to motor neurons. These motor neurons send motor impulses to the flexors and allows withdrawal.

Thus, the correct answer is 'Withdrawal reflex.'

Goose flesh in severe cold

biology nervous system of man reflex action innate and learned behaviour coordination in human beings- chemical control

  1. Reduces heat loss from body

  2. Increases heat loss from body

  3. Protects animal from external shocks

  4. Decreases activity of sweat glands

Show answer
Correct Option: A
Explanation:

A person experiences goose bumps in the presence of extremely cold temperatures. Tiny muscles attached to each hair follicle contracts because of the stimulus of cold surroundings. The hair strands stand on the end due to this contraction of muscles. The contracted tiny muscles cause bunching of the skin around hairs, which results in bumps in the goose bumps. The goose bumps are helpful to reduce the heat loss from the body and it is a way of preserving body's heat by causing the hairs on the skin to stand up. 

Which of the following is not a component of the reflex?

biology nervous system of man reflex action innate and learned behaviour coordination in human beings- chemical control

  1. Receptor

  2. Effector

  3. Motor neuron

  4. Plexus

Show answer
Correct Option: D
Explanation:

Plexus is a powered weight loss supplement that mix with water and drink. Plexus is slim claimed to help you lose weight by making you feel more full. It is also claimed to help reduce blood sugar and cholesterol levels.

So, the correct option is 'Plexus'.

Choose the correct answer from the alternatives given.
Which of the following are the first and last elements in a spinal reflex?

biology nervous system of man reflex action innate and learned behaviour coordination in human beings- chemical control

  1. Axon and dendrite

  2. Sense organ and muscle effector

  3. Ventral horn and dorsal horn

  4. Motor neuron and sensory neuron

Show answer
Correct Option: B
Explanation:

  • Receptor - sense organ in the skin, muscle, or another organ.
  • Sensory neuron - carrier impulse within CNS
Interneuron - carrier impulse within CNS
  • Motor neuron - carrier impulse towards CNS
  • Effector - structure by which an animal responds.
So, the correct option is 'Sense organs and muscle effector'.